Jurnee Smollett-Bell as Rosalee in WGN America’s “Underground.” (Steve Dietl/WGN/Sony Pictures Television)

“Underground,” WGN America’s thrilling slavery-era drama, begins its second season Wednesday with a heightened sense of urgency — rooted in the past, but tethered to the present.

When it premiered last year, the show immediately stood apart from other ­Hollywood slave narratives, which have too often overlooked the true heroes of the United States’ darkest legacy. “Underground” creators Misha Green and Joe Pokaski built a story around those people — ordinary men and women who lived constantly in the shadow of horrific violence and death but summoned the courage to fight for their freedom.

“The revolution will not be televised,” Gil Scott-Heron told us in 1970, and his words remain true. But “Underground” isn’t asking us to “plug in, turn on and cop out.” It’s showing us what revolution looks like — and that it’s possible even in the most dire circumstances.

“Underground” happens to do so in the context of a fast-paced TV drama. This isn’t a PBS documentary. It’s well-informed by historical research, but it’s also entertainment — at turns poignant, heartbreaking, suspenseful and, dare I say, sexy. This season’s first episode begins with Beyoncé’s fiery anthem “Freedom,” continuing the show’s tradition of fusing period and modern music. Executive producer John Legend is set to make a cameo as the abolitionist Frederick Douglass.

“Underground’s” sophomore season finds escaped slaves Rosalee (Jurnee Smollett-Bell) and Noah (Aldis Hodge) continuing their journey toward freedom with the help of Harriet Tubman (Aisha Hinds). The famed Underground Railroad “conductor” was introduced in the first season’s exhilarating final scene.

Aisha Hinds as Harriet Tubman in “Underground.” (Steve Dietl/WGN/ Sony Pictures Television)

Season 2, which arrives on International Women’s Day, is more sure-footed than Season 1 in connecting past and present. It puts women at the center, with Rosalee working with abolitionists including Elizabeth Hawkes (Jessica de Gouw) and a “sewing circle” led by a welcoming but tough widow named Georgia (Jasika Nicole). This focus feels current in the wake of the Women’s March on Washington and amid discussions about feminism and intersectionality. The season premiere also comes days after Housing and Urban Development Secretary Ben Carson’s comments that likened slaves to immigrants pursuing “dreams and opportunity.”

Rosalee has two missions this season. The first is to reunite with Noah, with whom she fell in love before he was captured and imprisoned. She also sets out to rescue her mother, Ernestine (Amirah Vann), who was sent to a plantation in coastal South Carolina. Rosalee is forced to navigate treacherous terrain while evading the notorious slave-catcher Patty Cannon (Sadie Stratton).

Ernestine’s world all but crumbled last season when her eldest son, Sam, was lynched under the complicit knowledge of their slave master, Tom, with whom she had a sexual relationship. Season 2 finds her in an increasingly troubled mental state, as she agonizes over her inability to protect her children, including James, who was separated from her. She tries to take control of her own body — through sex, as she did with Tom — despite knowing it’s in vain.

Ernestine’s story line is complicated. Her struggle represents the particular brand of brutality faced by female slaves, whose bodies were treated as property and who perpetually risked losing their children to another plantation — or worse. Her story also accounts for a great deal of the show’s melodrama, which can seem out of place in a story about slavery.

But is it, really? However over the top, “Underground” is forcing us to consider that, for slaves, love, romance, family, mental health and life itself were always under pressure from the weight of injustice.

Season 2 gets off to a strong but intense start with its first three episodes. There are a number of surprises — and cliffhangers so jarring that fans might not want to wait a week to find out what happens.

In one episode, Patty Cannon, desperate to turn her hunting of black bodies into fame, tells a would-be biographer that “you can’t make a legend out of the truth.” In a way, that’s what “Underground” has done with Rosalee and her cohorts, who are based on accounts of real-life slaves. These are the people who should have been our heroes all along.

Underground (one hour) returns Wednesday at 10 p.m. on WGN America.